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Generation and Spectroscopic Profiles of Stable Multiarylaminium Radical Cations Bridged by Fluorenes
No full textDesign and Syntheses of Donor-Bridge-Acceptor Molecular Frameworks in the Applications of Thermochromism, Intervalence Charge Transfer, and Molecular Switch
No full text本文的研究目的是設計並合成具有推電子基-架橋-拉電子基的分子系統，並分為三個部分探討熱致變色現象、價態間電荷轉移機制以及作為分子開關之研究。在第一部分的研究是發展具有可逆性之熱致變色分子，如圖（1）所示，藉由改變不同的共軛架橋官能基，探討化合物在質子化後的熱致變色行為。由吸收光譜和螢光光譜的結果顯示，質子化後產生紅位移現象，並且螢光產生了驟息現象。在乙腈溶液中可藉由升溫回復至中性狀態，而在二氯甲烷溶液中，則是需要降低溫度使其回復至中性狀態。氫核磁共振光譜得知，質子化的位置在苯並噻唑的氮原子上，並由變溫實驗可得知氫訊號可隨溫度升高而回復至原本的中性狀態。當架橋分子的芳香性越差，中性狀態和質子化狀態之間的反應焓差異也較小，因此具有較佳之熱致變色特性，並且擁有較好的可逆性。
第二部分的研究是以銅二價金屬離子作為氧化劑將苯胺衍生物氧化形成自由基陽離子，如圖2所示，以芴作為連接苯胺基的架橋分子發現到當其中一個苯胺被氧化形成自由基陽離子時，會產生價態間電荷轉移的現象，因此在吸收光譜中會在近紅外光區有吸收峰的生成。由電子自旋共振光譜實驗得知，自由基陽離子的形成可藉由量測未成對電子訊號證明其存在。除了芴之外，引入不同的架橋分子對於電荷轉移現象也有明顯的影響。
具有光致變色特性的二噻吩乙烯除了可經由照光進行結構之間的轉換，氧化還原的方式也可達到同樣的目的，原因在於經由所產生自由基陽離子可驅使開環或合環反應的進行。在本文的研究中在二噻吩乙烯引入二甲苯胺基並修飾不同的推拉電子基集團，如圖3所示，以銅二價金屬離子作為氧化劑可將苯胺進行氧化形成自由基陽離子，在合環狀態在形成自由基陽離子後可進一步做開環反應形成開環狀態的自由基陽離子。除此之外，由光譜電化學實驗可得到同樣的實驗結果，並藉由還原電位回到原本的中性狀態，電子自旋共振光譜說明開環反應的過程中有自由基陽離子的生成。The research is focused on the design and synthesis of donor-bridge-acceptor systems in the application of thermochromism, intervalence charge transfer, and molecular switches. In the first part of the study is the development of donor-bridge-acceptor systems as reversible thermochromic applications. As shown in Figure 1, different π-conjugation bridged fragments explore the thermochromic properties in the protonated form. From UV-vis and fluorescence spectra, these molecules show the red shift and the fluorescence quenching after protonation. In acetonitrile solution, the protonated forms can return to the corresponding neutral forms by heating. In dichloromethane solution, it has to reduce the temperature back to its neutral forms. Variable temperature 1H NMR spectroscopy demonstrates that protons of benzothiazole and bridged fragments can restore to the original neutral form at high temperatures in acetonitrile solution. When the aromaticity of bridges is worse, the enthalpy different between the neutral form and the protonated form is smaller, and therefore it can be better thermochromic properties, and has a good reversibility.
The second part of the study develops Cu(ClO4)2 as an oxidant to oxidize arylamine derivatives to corresponding radical cation. As shown in Figure 2, fluorene as a bridged fragment connecting two arylamines demonstrates that intervalence charge transfer will take place when one of arylamine is oxidized to form radical cation. Therefore, the absorption spectra will observe absorption band in the near infrared region. Moreover, electron spin resonance experiments can measure the signal of unpaired electron to prove the formation of arylaminium radical cation. In addition to fluorene, the introduction of different bridged fragments also can offer more electron coupling information for charge transfer phenomenon.
Photochromic properties of dithienylethene can change its structures reversibly by stimuli like as light and redox. It is because that the generation of radical cation can drive the ring-opening or ring-closing reactions. In this study, we introduce the ditolylamine and different functional groups on dithienylethene (Figure 3). Cu(ClO4)2 as the oxidant can oxidize DTEs derivatives to form corresponding radical cation. In the ring-closed form of DTEs derivatives, arylaminium radical cations can trigger ring-opening reaction and form corresponding ring-opened form. In addition, spectroelectrochemical experiments demonstrate the same results, and the reduction potential can return to the original neutral form. Electron spin resonance spectroscopy shows ring-opening reaction in the process of radical cation generation
Synthesis of Coumarin Derivatives for Metal Ions Sensing
No full text本文主要是研究針對金屬離子有偵測能力的螢光感測器，利用香豆素（coumarin）作為訊號轉換單元，改變不同的辨識單元，以研究不同的辨識單元對於金屬離子選擇性的變化。以聚乙醇（polyethylene glycol）為辨識單元合成化合物1、2，二氮雜18-冠醚-6（diaza-18-crown-6）為辨識單元合成化合物3、4，以及引入不同的酚類官能基，合成化合物5-8，最後是以香豆素-6作為訊號轉換單元，在胺基上3個苯環取代基的鄰位各引入1個羥基的化合物9。
由實驗結果可知，化合物1對於銅和汞離子均有明顯的螢光增強現象，尤以銅離子螢光增強11倍最為明顯。化合物3對於鉛和銅離子螢光增強較為明顯，在加入鉛離子時，在螢光光譜上有紅位移現象發生，但在加入銅離子時，則產生了藍位移現象。在化合物5-8中，則是對於多種金屬離子均有螢光增強表現，另外在有機溶液及水溶液的共溶劑系統中，也有不錯的螢光增強表現。最後在化合物9中，針對銅離子具有高度的選擇性，在螢光訊號上增強了12倍左右。The main objective of this thesis is to design and synthesize fluorescent chemosensors for detection of metal ions. Coumarin fluorophores were chosen to serve as signal transducer. Various recognition units were coupled with the signal transducer units in order to investigate how these recognition units influence metal ion selectivity. Accordingly, fluorescent chemosensor 1-9 were prepared. Both fluorosensor 1 and 2 consist of polyethylene glycol as recognition unit. The preorganized recognition unit, diaza-18-crown-6, was employed in the case of fluorosensors 3 and 4. In order to improve water solubility and provide additional interaction elements for metal ions, a lariat phenolic group was introduced in the case of 5-8. Fluorosensor 9 features three phenolic groups around nitrogen center as recognition center in lieu of diethyl amino moiety of coumarin-6.
Experimental results demonstrated that fluoresensor 1 displayed copious fluorescence enhancement in the presence of Cu2+、Hg2+, respectively. Fluoresensor 3 showed tight binding with Pb2+、Cu2+ with fluorescence enhancement, too. In the case of Pb2+, red-shift in fluorescence spectrum was observed, whereas blue shift was evidenced in the presence of Cu2+ ion. Fluorosensors 5-8 displayed high specificity for heavy metal ions, especially Pb2+. Either in organic solutions or oraganic/buffer cosolvent systems, large fluorescent enhancement was evidenced for Pb2+. Fluorosensor 9 displayed high selectivity for Cu2+ with 12-fold fluorescence enhancement in acetonitrile.目錄
目錄………………………………………………………………………I
圖目錄…………………………………………………………………III
表目錄…………………………………………………………………VII
流程圖目錄………………………………………………………….VIII
簡稱用語對照表……………………………………………………….IX
中文摘要………………………………………………………………..X
英文摘要……………………………………………………………..XII
緒論………………………………………………………………………1
第一章 螢光金屬離子感測器之原理及應用………………………….4
1.1前言………………………………………………………………….4
1.2螢光感測分子作用機制…………………………………………….5
1.2.1光誘導電子轉移……………………………………………….5
1.2.2光誘導電荷轉移………………………………………………..6
1.2.3準分子…………………………………………………………..7
1.2.4 激發態分子內質子轉移………………………………………8
1.3銅、鉛、汞離子的介紹………………………………………………9
1.3.1以銅離子作為螢光感測器的介紹……………………………10
1.3.2以鉛離子作為螢光感測器的介紹……………………………14
1.3.3以汞離子作為螢光感測器的介紹……………………………16
第二章 香豆素衍生物金屬離子感測器之合成………………………19
2.1 香豆素衍生物金屬感測分子之合成策略……………………….19
2.2 香豆素衍生物金屬感測分子之合成探討……………………….19
第三章 結果與討論………………………………………………….39
3.1化合物1、2的光譜研究及結果討論………………………………39
3.2化合物3的光譜研究及結果討論………………………………….47
3.3化合物4-8的光譜研究及結果討論……………………………….55
3.4化合物9的光譜研究及結果討論………………………………….62
第四章 結論……………………………………………………………70
實驗部份……………………………………………………………….71
參考文獻………………………………………………………………112
附錄……………………………………………………………………117
圖目錄
圖1-1：光誘導電子轉移機制（PET）示圖……………………………6
圖1-2：光誘導電荷轉移機制（PCT）示圖……………………………7
圖1-3：pyrene衍生物螢光感測分子結構…………………………….8
圖1-4：lariat crown ethers pyrenyl methyl螢光感測分子結構.8
圖1-5：激發態分子內質子轉移機制於不同溶劑下螢光變化示意圖.9
圖1-6：應用激發態分子內質子轉移偵測金屬離子之機制………….9
圖1-7：硫原子冠醚香豆素衍生物化學結構圖……………………..10
圖1-8：CueR和銅離子結合後造成螢光增強之機制…………………11
圖1-9：Ligand 1和Ligand 2結構及偵測銅離子之機制……………12
圖1-10：pentiptycene-bispyrenyl和銅離子結合之示意圖………13
圖1-11：rhodamine B hydrazide和銅離子反應後形成rhodamine B 之機構………………………………………………………….......14
圖1-12：香豆素衍生物之化學結構及與鉛離子結合之示意圖…….15
圖1-13：polyamidoamine結構及與鉛離子結合之示意圖………….15
圖1-14：calix[4]arene衍生物結構及和鉛離子結合模式…………16
圖1-15：4-aminonaphthalimide衍生物的結構及與汞離子結合的示意圖………………………………………………………….........17
圖1-16：3,9-dithia-6-azaundecane moiety fluorescein結構示意圖……………………………………………………………….......18
圖1-17：8-氫氧基奎林衍生物結構示意圖………………………...18
圖3-1：化合物2及化合物與16種金屬離子結合之螢光變化圖…….40
圖3-2：化合物1與金屬離子結合的吸收光譜和螢光放射光譜…….40
圖3-3：化合物1與銅離子結合之吸收光譜和螢光光譜…………….42
圖3-4：化合物1與汞離子結合之吸收光譜和螢光光譜…………….42
圖3-5：化合物1與金屬離子結合示意圖…………………………….43
圖3-6：化合物1和銅離子（a）、汞離子（b）之等溫螢光滴定圖.44
圖3-7：化合物1與銅離子（a）、汞離子（b）的Hill plots……44
圖3-8：化合物1與銅離子結合之紅外線光譜……………………….45
圖3-9：化合物1與汞離子結合之紅外線光譜……………………….46
圖3-10：化合物1、3與16種金屬離子結合之螢光變化圖………….47
圖3-11：化合物3與鉛離子結合之吸收光譜和螢光光譜……………48
圖3-12：化合物3與銅離子結合之吸收光譜和螢光光譜……………49
圖3-13：化合物3和鉛離子(a)、銅離子(b)之等溫螢光滴定圖……50
圖3-14：化合物3與鉛離子(a)、銅離子(b)的Hill plots…………50
圖3-15：化合物3與鉛離子之Job’s plot…………………………51
圖3-16：化合物3與鉛離子結合之紅外線光譜………………………52
圖3-17：化合物3與銅離子結合之紅外線光譜………………………52
圖3-18：化合物3加入飽和當量數金屬離子之螢光影像圖…………53
圖3-19：以NaCN競爭出化合物3中的鉛離子之吸收光譜及螢光光譜
………………………………………………………………………….53
圖3-20：以NaCN競爭出化合物3中的銅離子之吸收光譜及螢光光譜
………………………………………………………………………….54
圖3-21：化合物3-8與16種金屬離子結合之螢光變化圖……………55
圖3-22：化合物5、6與鉛離子結合之吸收光譜和螢光光譜……….56
圖3-23：化合物7、8與鉛離子結合之吸收光譜和螢光光譜……….57
圖3-24：化合物5、6和鉛離子之等溫螢光滴定圖………………….57
圖3-25：化合物7、8和鉛離子之等溫螢光滴定圖………………….58
圖3-26：化合物5、6與鉛離子的Hill Plots……………………….58
圖3-27：化合物7、8與鉛離子的Hill Plots……………………….58
圖3-28：化合物5、6與鉛離子之Job’s plot………………………59
圖3-29：化合物7、8與鉛離子之Job’s plot………………………59
圖3-30：化合物5、7加入飽和當量數鉛離子之螢光影像圖……….60
圖3-31：化合物5-6與飽和當量的鉛離子於pH = 7.0-10.0緩衝溶液中之螢光變化圖……………………………………………………….61
圖3-32：化合物7-8與飽和當量的鉛離子於pH = 7.0-10.0緩衝溶液中之螢光變化圖……………………………………………………….61
圖3-33：化合物7與鉛離子於pH = 8.0緩衝溶液中之吸收光譜及螢光光譜…………………………………………………………………….61
圖3-34：化合物8與鉛離子於pH = 8.5緩衝溶液中之吸收光譜及螢光光譜…………………………………………………………………….62
圖3-35：化合物9、PTC6、coumarin 6與16種金屬離子結合之螢光
變化圖……………………………………………………….63
圖3-36：化合物9與銅離子結合之吸收光譜和螢光光譜……………64
圖3-37：化合物9和銅離子之等溫螢光滴定圖………………………64
圖3-38：化合物9與銅離子的Hill plots……………………………64
圖3-39：化合物9與銅離子之Job’s plot………………………….65
圖3-40：化合物9與銅離子結合之紅外線光譜………………………66
圖3-41：化合物9加入飽和當量數銅離子之螢光影像圖……………67
圖3-42：化合物9與5當量的銅離子於pH =2.5-10.5緩衝溶液中之螢
光變化圖…………………………………………………….68
圖3-43：化合物9與銅離子於pH=6.2緩衝溶液中之吸收光譜及螢光
光譜………………………………………………………….68
圖3-44：化合物9和銅離子之等溫螢光滴定圖………………………69
圖3-45：化合物9與銅離子的Hill plots……………………………69
表目錄
表一：化合物1、2與16種金屬離子結合的波長及螢光強度變化….41
表二：化合物1與銅離子及汞離子結合之比較………………………46
表三：化合物3與鉛離子及銅離子結合之比較………………………54
流程圖目錄
流程圖（一） 化合物1之逆合成……………………………………20
流程圖（二） 化合物2之逆合成……………………………………23
流程圖（三） 化合物3之逆合成……………………………………26
流程圖（四） 化合物4之逆合成……………………………………30
流程圖（五） 化合物5-8之逆合成…………………………………33
流程圖（六） 化合物9之逆合成……………………………………3
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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